What is Strain Energy? -IQ4

The external work done on an elastic member in causing it to distort from its unstressed state gets transformed into strain energy, which is a form of (PE) potential energy.
The strain energy in the form of elastic deformation is mostly recoverable in the form of mechanical work.

What are the kind of materials you have used - IQ 1 - LS-Dyna

What are the kind of materials you have used?

MATL1 -This is an isotropic elastic material, also allows modelling of fluids.
MAT 20 - Parts made from this material areconsidered to belong to a rigid body.
MATL 24 - Elasto plastic mat with arbitrary Stress Vs Strain curve and arbritary strain rate dependancy. Also failure based on plastic strain or minimum time step can be dfeined.
MATL57 - for highly compressible low density foam.
MATL 83 - Rate effects can be modelled in low and med density foams. Hysteric unloading behaviour in this model is a function of rate sensitivity with the most rate sensitivity foams providing the largest hysterisis and vice versa.




IQ Stands for interview questions

I have mentioned it in terms of Ls-Dyna, if you can explain the same in terms of Abacus/Ansys, please do post in comments

How to start preparing for the interview - II

Next about the performance requirements.

Well here I'm speaking more in terms of LS dyna as that is my tool of experience.

Global energy, Understand how the energy curves vary for each load case. For example how would the energy curve look for a quasi static load like SBA and how it would vary for a dynamic case like pendulum crash. Why does it differ?

Learn to draw a schematic diagram of the vehicle in terms of the load path.
For example from the bumper beam, towards the crush cans and then the rails etc, or for the same load case (full frontal) if we look at it from a slighter higher position, the load path is from the radiator, then the shotgun, hinge pillars etc.

If the frontal impact starts of with a force of 200 kN how does it get transferred towards the end of the vehicle.